Effect of different contrast administration protocols on contrast enhancement and image quality in CT scan

Abstract

Objective The aim of this study is to compare the effect of different contrast administration protocols practiced in Advanced Medical and Dental Institute, Universiti Sains Malaysia (Group A) and Hospital Pulau Pinang, Malaysia (Group B), on contrast enhancement and image quality in computed tomography scan. The two protocols were fixed time delay (FTD) with fixed volume (FV), and automatic bolus tracking (ABT) with weight based volume (WBV) contrast administration. Quantification of contrast enhancement’s magnitude in four different anatomical structures was measured in Hounsfield Unit (HU) and based on 5-point scale (1=poor, 5=excellent), the images were rated qualitatively.Results Mean enhancement values of all structures in Group B was higher compared to Group A (p = < 0.001). Mean of quality rating between the two groups was statistically not significant (p = 0.185). There was a weak correlation between HU values and administered contrast volume (r = 0.152). It can be concluded that FTD with FV protocol is non inferior to ABT with WBV protocol as it yielded higher degree of contrast enhancement. There was no significant difference between the two protocols in term of qualitative assessment although ABT with WBV protocol had higher mean grading in image quality.